> Is it the same tangent than a point who will be near the extremity and
> the extremity but "on" the curve?
> Seems yes, but I ask the question :)

Yes, the way NURBS curves work is the end tangent direction of the curve is defined by the direction of the last 2 control points.

But just to be clear - a point on the curve that is near the end but a small distance away from it will not have this tangent quite yet - it is only the very end of the curve that has this tangent. But I think that you have shown that in your graphic. As you move closer and closer along the curve towards the end point, the curve's tangent at that point will get closer and closer to the line between those 2 points.

- Michael